Question: Khan.scratchpad.disable(); To move up to the maestro level in his piano school, Ishaan needs to master at least $80$ songs. Ishaan has already mastered $16$ songs. If Ishaan can master $4$ songs per month, what is the minimum number of months it will take him to move to the maestro level?
Explanation: To solve this, let's set up an expression to show how many songs Ishaan will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Ishaan Needs to have at least $80$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 80$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 80$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 4 + 16 \geq 80$ $ x \cdot 4 \geq 80 - 16 $ $ x \cdot 4 \geq 64 $ $x \geq \dfrac{64}{4} = 16$ Ishaan must work for at least 16 months.